How to make a planet show more details whenever you get closer to it

i have no idea how to do this but here is a video Procedural Planet Generator Tech-Demo, Houdini to Unity, Graduation project - YouTube about the first 10 seconds shows me what i mean by detail. i dont know if its me or i just dont know how to google the answer.

i would like a guide on how to create that, im unfamiliar with cameras but i think i can script if needed.

You need to use a LOD system to do this. It is very easy to do a basic version of this